GDB调试c++程序
作者：互联网
示例文件main.cpp：
#include <iostream>
using namespace std;
int main(int argc,char *argv[])
{
cout << "hello gdb" << endl;
return 0;
}
目录结构：code
lee@lee-PC:~/code$ tree
.
├── bin
├── lib
└── src
└── gdb
└── mian.cpp
4 directories, 1 file
vim下直接在编辑界面+编译：:! gcc mian.cpp -o main
using namespace std;
void Test()
{
cout << "test function" << endl;;
}
int main(int argc,char *argv[])
{
cout << "hello gdb" << endl;
Test();
cout << "gdb end" << endl;
return 0;
}
~
:!g++ main.cpp -o main
GDB常用指令;
bt 查看函数调用的占空间信息，当程序down掉后，可以同步哦bt命令查看程序是从哪里down掉的。
lbirpnsc
| 命令格式 | 作用 |
|---|---|
| list<行号>|<函数名> | 查看指定位置的程序源代码 |
| break<行号>|<函数名> |<条件表达式> | 设置断点 |
| delete <断点号> |<断点范围> | 断点的删除 |
| lear | 删除所在行的过个断点 |
| info break | 显示断点信息 |
| run | 运行程序 |
| print <表达式>|<变量> | 查看程序运行时对应表达式和变量的值 |
| next | 单步恢复程序运行，但不进入函数调用 |
| step | 单步恢复程序运行，且进入函数调用 |
| continue | 继续执行函数，知道函数结束或者遇到新的断点 |
指令：list
lee@lee-PC:~/code/src/gdb$ g++ main.cpp -o main
lee@lee-PC:~/code/src/gdb$ ls
main main.cpp
lee@lee-PC:~/code/src/gdb$ ./main
hello gdb
test function
gdb end
lee@lee-PC:~/code/src/gdb$ gdb main
GNU gdb (Debian 8.2.1-2+b1) 8.2.1
Copyright (C) 2018 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from main...(no debugging symbols found)...done.
(gdb) l
No symbol table is loaded. Use the "file" command.
(gdb)
执行一下指令
g++ main.cpp -o main ->
gdb main ->
l
以上list(l)没有符号表被载入，是什么原因？
因为编译的时候需要指定Debug 还是Release，是否需要把调试信息编译进去，g++默认的时候调试信息不会被编译进去
-g会把代码编译进去，把代码与二进制之间的关系编译进去，这样二进制指令执行到哪一行，同时也知道执行的代码到哪一行，
g++ main.cpp -o main -g ->
gdb main ->
l
以上操作，l指令的时候才会显示出代码，一直l就会显示完所有的代码:
lee@lee-PC:~/code/src/gdb$ g++ main.cpp -o main -g
lee@lee-PC:~/code/src/gdb$ gdb main
GNU gdb (Debian 8.2.1-2+b1) 8.2.1
Copyright (C) 2018 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
--Type <RET> for more, q to quit, c to continue without paging--
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from main...done.
(gdb) l
1 #include <iostream>
2 using namespace std;
3 void Test()
4 {
5 cout << "test function" << endl;;
6 }
7 int main(int argc,char *argv[])
8 {
9 cout << "hello gdb" << endl;
10 Test();
(gdb)
list后面跟函数名：
(gdb) list Test
1 #include <iostream>
2 using namespace std;
3 void Test()
4 {
5 cout << "test function" << endl;;
6 }
7 int main(int argc,char *argv[])
8 {
9 cout << "hello gdb" << endl;
10 Test();
(gdb)
list后面跟行号：
(gdb) list 3
1 #include <iostream>
2 using namespace std;
3 void Test()
4 {
5 cout << "test function" << endl;;
6 }
7 int main(int argc,char *argv[])
8 {
9 cout << "hello gdb" << endl;
10 Test();
(gdb)
指令：break，设置断点
- 接行号
(gdb) break 5
Breakpoint 1 at 0x401176: file main.cpp, line 5.
(gdb) break 10
Breakpoint 2 at 0x4011c0: file main.cpp, line 10.
(gdb) break 11
Breakpoint 3 at 0x4011c5: file main.cpp, line 11.
(gdb) info b
Num Type Disp Enb Address What
1 breakpoint keep y 0x0000000000401176 in Test() at main.cpp:5
2 breakpoint keep y 0x00000000004011c0 in main(int, char**) at main.cpp:10
3 breakpoint keep y 0x00000000004011c5 in main(int, char**) at main.cpp:11
- 接函数名(函数的入口设置断点)
(gdb) break Test
Note: breakpoint 1 also set at pc 0x401176.
Breakpoint 4 at 0x401176: file main.cpp, line 5.
(gdb) info break
Num Type Disp Enb Address What
1 breakpoint keep y 0x0000000000401176 in Test() at main.cpp:5
2 breakpoint keep y 0x00000000004011c0 in main(int, char**) at main.cpp:10
3 breakpoint keep y 0x00000000004011c5 in main(int, char**) at main.cpp:11
4 breakpoint keep y 0x0000000000401176 in Test() at main.cpp:5
删除一号断点：
(gdb) delete 5
No breakpoint number 5.
(gdb) delete 1
(gdb) info break
Num Type Disp Enb Address What
2 breakpoint keep y 0x00000000004011c0 in main(int, char**) at main.cpp:10
3 breakpoint keep y 0x00000000004011c5 in main(int, char**) at main.cpp:11
4 breakpoint keep y 0x0000000000401176 in Test() at main.cpp:5
程序运行：run，到第一个断点处停止，此处位函数入口的断点，可以跳过(next)，可以进入(step)
(gdb) run
Starting program: /home/lee/code/src/gdb/main
hello gdb
Breakpoint 2, main (argc=1, argv=0x7fffffffcc18) at main.cpp:10
10 Test();
(gdb)
next: 执行下一行代码，但是不进入函数
(gdb) next
Breakpoint 4, Test () at main.cpp:5
5 cout << "test function" << endl;;
(gdb) d 4
(gdb) step
test function
6 }
(gdb)
从结果中看出，在到达函数调用处的代码时，如果函数中设置断点，next的时候会直接进入到函数代码；如果删除断点，step才会进入到函数否则，使用next就是直接执行完此处函数（当成一行代码）
- continue:从一个断点到下一个断点
Breakpoint 2, main (argc=1, argv=0x7fffffffcc18) at main.cpp:10
10 Test();
(gdb) continue
Continuing.
test function
Breakpoint 3, main (argc=1, argv=0x7fffffffcc18) at main.cpp:11
11 cout << "gdb end" << endl;
(gdb)
- 接条件表达式
//-----------------------------------------------------------------------
其他知识点：window共享出来的目录是 nobody nogroup
chmod 777 * -R,当前目录下所有文件及其子文件的权限设置
标签：lee,GDB,c++,Test,gdb,cpp,main,断点,调试 来源： https://blog.csdn.net/chengfenglee/article/details/112058608